1. Industrial useful field
This invention relates to a clutch disc in which a rotational rupture strength (burst strength) of a facing members is improved.
2. Prior art and its problem
In order to prevent a facing member from being ruptured due to a strong centrifugal force caused by a high engine speed, it has been desired to improve a rotational rupture strength of the facing member. Therefore, a stiffening plate 2 consisting of an annular disc-like aluminum plate having plate thickness of 1.0 mm has conventionally been glued to a backside of an annular facing member 1 as illustrated in FIG. 8, so as to stiffen the facing member 1 to improve the rotational rupture strength of the facing member 1
However, the structure of FIG. 8 has required much labor due to a comparatively large thickness of the stiffening plate 2 and increased manufacturing cost due to expensive aluminum material. Further, an inertial force acting on the facing member 1 has been increased by the weighty stiffening plate 2, so that the rotational rupture strength of the facing member 1 has not been improved satisfactorily or feeling of change shifting would have been worsened.